<html xmlns="http://www.w3.org/1999/xhtml" xmlns:svg="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<head>
<style>
  div {
    width: 100px;
    height: 100px;
    clip-path: url(#c1);
    background-color: blue;
    opacity: 0.5;
  }
</style>
</head>
<body>
  <div/>
  <svg:svg height="0">
    <svg:clipPath id="c1">
      <svg:rect x="0" y="0" width="50" height="100"/>
    </svg:clipPath>
  </svg:svg>
</body>
</html>
